Probably something like a 12w3v2 then.
http://mobile.jlaudio.com/products_subs.php?series_id=12
These used to be ~$500 rrp, they have just been superceded by the v3 model. So around $350 would be about right now.
There are three versions, all dual voice coil, 2 ohm, 4 ohm, 6 ohm. Once you know this, the most suitable amp is easy to pick.
JL recommend sealed enclosures of ~1.25 cubic foot (35.4l) or ported enclosures of 1.75 cubes (49.6l) tuned to 30.8 Hz. I like a little bigger for both and the port tuning a bit higher for daily use, around 35 Hz.
I have a 10w3v2-d2. It was the first sub that i bought. I have had others since and always go back to the w3. I have had it in a few different enclosures. The one i like best is a ported enclosure about .5 cubes bigger than jl recommendations, tuned to ~36 Hz.
Grab it! They are great sounding subs.
Cheers